Cutout for series lamps



D66. 29, 1931 BUTLER 1,839,084

CUT-OUT FOR SERIES LAMPS Filed Oct. 10, 1929 Inventor Her-m5 E BuCLer',

b5 HLs Attorneg.

Patented Dec. 29, 1931 PATENT OFFICE;

- HENRY E. 311mm or scum, Yam; AssIGNon TO-GENERALBLECTBIO comm, 1 A. conrozmrron, or nnw YORK v r v cu'rou'r m snares LAMBS Application sue OctoberiO; 1029. Serial No. 898,765.

are extinguished and it then becomesnecessaryto test thelampsin the string successively until the; burned-out lamp is 1 found and then replace. it before the string .cannhe put "in into service again. This is annoying, espe daily if the'lamps are located; so that they are not-readilyaccessible,.but in spite oii such difliculty series strihgsforthe, purpose specified are most commonly used hecaiuse they can. be provided: at. substantially lower'cost than; strings: of. parallel connected lamps- Film cutouts for series lighting; circuits. are

-well known and: are in common use in connection with, Series street-lighting circuits,

-anrlthis, of course is av-remedy, for the difiiculty'set-forth above. Howevemnone ofthe arrangements-in use atthe;v present time are suitable ton-low.- voltage series lamps because, amongother things, ofi 'theirihighcosts The object ofmy present invention, is to provide an improved construction-. and, arrangement oi filmmutoutwhich is so simple inn.structure, lowgin: cost, and easy to use, that it. becomes practical for use in connec- 5152121011 with strings of lightssuch asthoseused for; Ghristmas tree lighting, and. for a consideration of; whatl; believe tobe novel and my invention, attention: is directed toithe following specification and the; claims app ded? there o.

' In the drawings, Fig, I is a perspective viewof a, light of the-type-used for Chris masj'tree; lighting; provided with a filmcutout; structure embodying my invention; Fig.

41:"; 2 is an exploded view ofcertain of. the parts which; goito; makeup the film cutout, device, and Fig. 3 is a longitudinal, sectional View partly: broken away of the complete device.

Referring to the drawings, 1 indicates an 1 lib electric lamp such as a Christmas tree lamp,

2 indicates the lamp socket and receptacle, and 3 and 4 indicate the two lead wires. It will be understood that a number of lamps similar to lamp 1 are connected in series by the lead wires to form a string. The lead ar dielectricfilmwhichmay be intheform of wires are, insulated; wires, and in the drawing5 indicatesthe conductors ofthe wires.

,According to, theembodiment of. my in- ,ventionsil-lustrated in the drawings-,1 provide a block 6 of insulating: material having,

a longitudinally extending groove 7 therein of aflwidth adapted to receive the wires}! ands Preferably also the blockisa provided with: a transversely" extending groove 1 8 which...communicates with groove 7 and go throughwhich the wires 3 and 4%:project so that-the block 6 may extend transversely of the lamp 1, the-lamps 1 hanging down below the-block. Also groove 7 may be provided: at its innermost; endwith a depression or ,re- 1 cess 9 adapted to partially receivethewine soas to'hold it in fi'xed position in the groove. The; groove 8, in'substance dividesthe groove into two grooves, one for eachl'ead Wire, and viewed from this aspect it may be con-e170 sideredthat the block. is provided with two grooves, one for each wirel Inthe-uppersM- faceof the block isa recess 10 at the two ends of which are located, connectors-'11 and" 12, adapted tomake electrical contact: with the conductors 5 ofthelead wires3 and 4.- These connectors may be with advantage in: the form of screws having pointed endsas indicated at 13 in Fig. 3, whereby the. screws may be brought into electrical contact with these conductors. by forcing the pointed ends through the insulation-as is shown at thelefthand? side: of the F ig; 3.v J oiningi the two connectors is a conducting member 14- which may be in the form of a suitable; resistance and which, if desired,.may be wound; on a. carrying member 15; At its two ends the conducting, member 14 isconnected to washers 16 locatedbeneath the heads ofascrews 11 and; 12.

member 14 form: a conductor. connectingthe two'wires which conductor is in 'shunt tothe lamp filament and in this conductor I provide an insulating coating on one OflthGrPllltS-Offiii a character such: that at normalvoltage it 7 remains intaotbut incaseit is subjected to avoltagea certain amount higher than normal itbreaks down or punctures, this being fthe; well understood manner. in which a. 100

electric filmbe provided in the shunt conductor. The conducting member 14 may have a resistance equal substantially to that of the lamp filament so that when inserted into the series circuit, the brightness at which the remaining lamps burn will not be affected,

or it may have a higher resistance whereby when inserted into the circuit it will dim somewhat all the lamps, thus serving as an indication that a lamp has burned out. Or, if desired, conducting member 1 1 may have relatively small resistances, serving then only as a connector.

In the use of the invention, a film cutout is connected in parallel with each lamp of the string, as shown in Figs. 1 and 3. This is easily done with the use only of a screw driver, it being necessary merely to place the wires 3 and 4 in the grooves and turn down the screws. Recess 9 serves to hold the wires from sliding sidewise when the pointed ends of the screws are being forced through the insulation on the wires. When .a lamp burns out, the dielectric film of its film cutout breaks down or punctures due to the higher voltage to which it is subjected and forms a short circuit around the burned out filament. The rest of the string of lamps will continue to burn. At any time anew lamp may be substituted for the burned out lamp, and a new film cutout substituted for the punctured one.

By my invention I provide a film cutout which is very simple in structure, easy to use and capable of being manufactured at low cost. In addition, it has the advantage that it may be used in connection with any string of lamps, its use in no way modifying or changing existing structures. Also, it is so simple that any one can easily apply it to a string of lamps.

In accordance with the provision of the patent statute I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A film cutout for series lamps comprising a block having groove means adapted to receive a pair of lead wires, spaced contacts carried by the block and insulated from each other for engagement with the conductors of the lead wires, and means including a dielectric film connecting said contacts.

2. A film cutout for series lamps comprising a block havin groove means adapted to receive a pair of lead wires, spaced contacts carried by the block and insulated from each other for engagement with the conductors of the lead wires, and means including a dielectric film and a resistance in series there with connecting said contacts.

3. A film cutout for series lamps comprising a block having groove means adapted to receive a pair of lead wires, spaced contacts having pointed ends carried by the block, said pointed ends being adapted to pierce the insulation on a lead wire and make engagement with the conductor of the wire, and means including a dielectric film connecting said contacts.

4. A film cutout for series lamps comprising an insulating block having a groove portion for each of two lead wires, contact screws having ends which project into said groove Jortions, and means including a dielectric 'lm connecting said contacts.

5. A film cutout for series lamps comprising an insulating block having a groove portion for each of two lead wires, contact screws having ends which project into said groove portions, and means including a dielectric film and a resistance in series therewith connecting said contacts.

6. A film cutout for series lamps comprising an insulating block having a longitudinally extending groove and a transverse groove communicating therewith, said grooves being adapted to receive lead wires, spaced screws carried by the block and having ends which project into said grooves, and means including a dielectric film connecting said screws.

7. A film cutout for series lamps comprising a block, contacts carried by the block and insulated therefrom, said contacts being adapted for connection directly to the lead wires of an electric lamp, and means connecting said contacts, said means including a part coated with a dielectric film.

8. A film cutout for series lamps comprising a block, contacts carried by the block and insulated therefrom, said contacts being adapted for connection directly to the lead wires of an electric lamp, and means including a dielectric film and a resistance in series therewith connecting said contacts.

In witness whereof, I have hereunto set my hand this 9th day of October, 1929.

HENRY E. BUTLER. 

